In security devices it is desirable to automatically release locks having latch bolts or guarded latch bolts. Such bolts are carried by a door and are received in a strike which is closed by a jamb. Previously developed automatically released devices have required modification of the lip of the jamb in which the release mechanism was mounted. In addition, such prior devices were vulnerable to attack at the point where the release mechanism was exposed outside the door jamb.
A need has thus arisen for a release mechanism that is completely concealed within the door jamb. A need has further arisen for a release mechanism that will release the latch bolt even in the presence of strong forces against the door. Such forces against the door can be caused by thick weather stripping, by air pressure differential from an air conditioning system, or by a person applying force to the door during actuation of the release mechanism.